Connecting structure for medical use

Abstract

A connecting structure for medical use includes a male assembly 1 and a female connector 2 . The male assembly 1 includes a male connector 10 and a threadedly engageable cylinder 20 . A male luer portion 11 of the male connector 10 and a female luer portion 2 a of the female connector 2 are joined by turning the threadedly engageable cylinder 20 in a tightening direction in a state where a female screw 21 a of the threadedly engageable cylinder 20 and an engageable protrusion 2 c of the female connector 2 are threadedly engaged with each other. A torque limiting mechanism 50 is disposed between an operation cylinder 30 mounted on an outer periphery of the threadedly engageable cylinder 20 and the threadedly engageable cylinder 20 . Engageable teeth 51 are formed in an inner periphery of one end portion of the operation cylinder 30 over an entire periphery. A slit 54 is formed in one end portion of the threadedly engageable cylinder 20 . The slit is composed only of a straight portion extending from an end of the threadedly engageable cylinder in an axial direction. An area adjacent to the slit 54 is provided as an elastically deformable portion 52 . A first engageable claw 53 engageable with the engageable teeth 51 is formed in the elastically deformable portion 52.

The invention claimed is: 
     
       1. A connecting structure for medical use comprising:
 a male assembly; and 
 a female connector of a cylindrical configuration, 
 the male assembly including a male connector of a cylindrical configuration and a threadedly engageable cylinder rotatably coupled to the male connector, 
 the male connector including a male luer portion and a support portion arranged in a direction from a distal end to a basal end thereof in this order, 
 the threadedly engageable cylinder including a threadedly engageable portion and a mounting portion arranged in a direction from a distal end to a basal end thereof in this order, the mounting portion rotatably mounted on an outer periphery of the support portion of the male connector, the threadedly engageable portion including a female screw in an inner periphery thereof, the threadedly engageable portion disposed outside of the male luer portion in a radial direction, 
 the female connector including a female luer portion and an engageable protrusion formed in an outer periphery of the female luer portion, 
 the male luer portion and the female luer portion joined by turning the threadedly engageable cylinder in a tightening direction in a state where the female screw of the threadedly engageable cylinder and the engageable protrusion of the female connector are threadedly engaged with each other, 
 the connecting structure further comprising an operation cylinder mounted on an outer periphery of the threadedly engageable cylinder and a torque limiting mechanism disposed between the threadedly engageable cylinder and the operation cylinder; 
 the torque limiting mechanism transmitting a rotary torque of the operation cylinder in a tightening direction to the threadedly engageable cylinder; 
 the torque limiting mechanism allowing the operation cylinder to be turned idly with respect to the threadedly engageable cylinder when the rotary torque exceeds a predetermined torque; 
 the torque limiting mechanism including engageable teeth formed in an inner periphery of one end portion of the operation cylinder in an axial direction over an entire periphery and at least one first engageable claw protruded outward in a radial direction from an outer surface of one end portion of the threadedly engageable cylinder in an axial direction, the first engageable claw engageable with the engageable teeth; wherein 
 at least one slit is formed in the one end portion of the threadedly engageable cylinder, the slit composed only of a straight portion extending in the axial direction from an end of the threadedly engageable cylinder; 
 at least one of two areas of the one end portion of the threadedly engageable cylinder adjacent to the slit in a circumferential direction is provided as an elastically deformable portion having a lower elastic coefficient than the other areas of the one end portion of the threadedly engageable cylinder; 
 the first engageable claw is formed in an outer surface of the elastically deformable portion; and 
 the elastically deformable portion is deformed inward in the radial direction when the operation cylinder is turned idly and the first engageable claw is moved over the engageable teeth. 
 
     
     
       2. The connecting structure for medical use according to  claim 1 , wherein a dimension of the first engageable claw in the axial direction is shorter than that of the slit. 
     
     
       3. The connecting structure for medical use according to  claim 1 , wherein a dimension of the first engageable claw in the axial direction is longer than that of the slit. 
     
     
       4. The connecting structure for medical use according to  claim 1 , wherein the first engageable claw is disposed adjacent to the slit. 
     
     
       5. The connecting structure for medical use according to  claim 1 , wherein the first engageable claw is disposed spaced from the slit in the circumferential direction. 
     
     
       6. The connecting structure for medical use according to  claim 1 , wherein the first engageable claws are disposed at a location adjacent to the slit and at a location spaced from the slit in the circumferential direction. 
     
     
       7. The connecting structure for medical use according to  claim 1 , wherein:
 a loosening prevention mechanism is disposed between the support portion of the male connector and the mounting portion of the threadedly engageable cylinder, the loosening prevention mechanism prohibiting the threadedly engageable cylinder from being rotated in a loosening direction with respect to the male connector in a state where the male luer portion and the female luer portion are joined; 
 the loosening prevention mechanism includes ratchet teeth formed in one of the support portion of the male connector and the mounting portion of the threadedly engageable cylinder over an entire periphery, at least one elastic leaf formed in the other of the support portion and the mounting portion and a second engageable claw formed in the elastic leaf and engageable with the ratchet teeth; and 
 the elastic coefficient of the elastically deformable portion of the torque limiting mechanism is higher than an elastic coefficient of the elastic leaf of the loosening prevention mechanism. 
 
     
     
       8. The connecting structure for medical use according to  claim 7 , wherein:
 the ratchet teeth of the loosening prevention mechanism are formed in an inner periphery of the mounting portion of the threadedly engageable cylinder, the ratchet teeth disposed adjacent to the elastically deformable portion of the torque limiting mechanism in the axial direction; 
 the elastic leaf of the loosening prevention mechanism is formed in the support portion of the male connector; and 
 the second engageable claw is protruded outward in the radial direction and engaged with the ratchet teeth.